Code division multiple access (CDMA) communication systems are evolving from an early generation to a more advanced generation. In updating a system, one or more parameters associated with various operations of the system may change. The mobile stations in the more advanced system are also updated to operate within the new parameters. One of the early generation systems operates in accordance with the parameters defined in the TIA/EIA-95A/B standard, incorporated by reference herein. One of the more advanced systems operates in accordance with the, TIA/EIA-IS-2000-A standard, incorporated by reference herein. At the time of this application for a patent, a newer version of the TIA/EIA-IS-2000-A standard is under development and being released under TIA/EIA-IS-2000-B standard, incorporated by reference herein. A copy of the standards may be obtained by accessing the world wide web at the address: http://www.3gpp2.org, or by writing to TIA, Standards and Technology Department, 2500 Wilson Boulevard, Arlington, Va. 22201, United States of America.
A communication system has many different components. The operating parameters of each component are defined by the corresponding standard. A system may be partially updated by changing certain components to operate in accordance with the newer version of the corresponding standard. One of the mandate and essential features of the proposed TIA/EIA-IS-2000-B standard is providing message integrity of the communication between a mobile station and a base station. Message integrity guarantees the legitimacy of the sender of the message. To achieve message integrity, an Authentication and Key Agreement (AKA) procedure has been developed and defined in the relevant sections of the standard. An Authentication Center (AC) is a component that manages the authentication information related to the mobile stations operating in the system. The operating parameters of an interface between a mobile switching center (MSC) and the AC need to be upgraded from an earlier version for performing the AKA procedure. Without an MSC-AC interface upgrade, the upgraded mobile stations and the base stations, which are capable of performing the AKA procedure, can not actually perform the AKA procedure due to the lack of the system to carry the AKA information via the MSC-AC interface. As a result, message integrity can not be performed. Such a condition becomes a significant deployment problem when the base stations and mobile stations are upgraded to operate in accordance with the proposed TIA/EIA-IS-2000-B standard prior to upgrading the MSC-AC interfaces.
To this end as well as others, there is a need for a method and apparatus to allow the more advanced generation mobile stations and base stations to perform message integrity.